#!/usr/bin/env bash
# Build a singleuser image for JupyterHub from a given stack
# Usage:
# ./build-singleuser jupyter/scipy-notebook my-singleuser-image

set -e

V="0.2.0"
# get dockerspawner
if [[ ! -d dockerspawner ]]; then
  tgz="dockerspawner.tar.gz"
  wget -N https://github.com/jupyter/dockerspawner/archive/$V.tar.gz -O $tgz
  echo "8af14608ad30df4dfcced7c7be508d336d485d9c31af965dc84c5e882e19dfe4 *$tgz" | shasum -a 256 -c - || (echo "shasum mismatch $(shasum -a 256 $tgz)" && exit -1)
  tar -xzf $tgz
  mv dockerspawner-$V dockerspawner
fi

base="$1"
name="$2"
if [[ -z "$base" || -z "$name" ]]; then
  echo "Usage: build-singleuser [base image] [destination image]" >&2
  exit 1
fi
echo "building $name from $base"

singleuser=dockerspawner/singleuser
# copy single-user stack
sed -i "s@^FROM.*\$@FROM $base@" "$singleuser/Dockerfile"
docker build -t "$name" "$singleuser"
echo "built $name"